This invention relates to diagnosis and treatment of cancers, particularly, solid tumors.
Sager, 246 Science 1406, 1989, discusses tumor suppressor genes. The loss of tumor suppressor genes, or their inactivation, is oncogenic. That is, the loss of DNA encoding a tumor suppressor gene product, or the lowering of expression of a tumor suppressor gene gives rise to a cancerous condition. Sager generally describes the identification of such tumor suppressor genes. In particular, Sager describes the process of subtractive hybridization as a general method for recovering genes that are expressed in normal cells but not in closely related tumor cells. Sager further describes the isolation of three clones by subtractive hybridization of normal and cancerous mammary cells. The genes corresponding to these clones are expressed by all normal mammary epithelial cells, but not by any primary mammary tumors or mammary tumor cell lines. One such gene encodes keratin 5, which is said to be a valuable marker to distinguish normal and primary tumor cells in culture. Also identified is a gene encoding fibronectin, and a third gene identified as NB-1. Tumor suppressor genes are proposed to play a key role in cancer protection, and it is suggested that tumor suppressor genes provide a vast untapped resource for anti-cancer therapy.